Soil Geomorph

General term for light colored igneous and some metamorphic crystallin rocks. (Granite, Rhyolite, Felsite)

generally describes dark colored igneous rock with significant amounts of one or more ferromagnesian minerals, or to a magma with significant amounts of Fe and Mg. (Little quartz, feldspar, or muscovite.

• Cenozoic quaternary 1.6
• Tertiary 6.5
• Mesozoic Cretaceous 146
• Jurassic
• Triassic
• Paleozoic Permian 286
• Pennsylvanian 320
• Mississippian 360
• Devonian
• Silurian
• Ordovician
• Cambrian 570miyearsago